JP2006218574A - Surface coated cemented carbide cutting tool having hard covering layer exhibiting superior chipping resistance in high speed cutting of difficult-to-cut material - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a surface coated cemented carbide cutting tool having a hard covering layer exhibiting superior chipping resistance in a high speed cutting of a difficult-to-cut material. <P>SOLUTION: This surface coated cemented carbide cutting tool is (a) constituted of an upper-part layer and a lower-part layer both of which are composed of (Ti, Al, V)N on the surface of a cemented carbide body, and the upper-part layer and the lower-part layer have the layer thicknesses of 0.5-1.5 μm and 2-6 μm respectively; (b) the upper-part layer is provided with an alternate-layer structure of a thin layer A and a thin layer B both of which have the layer thickness of 5-20 nm and are composed of the (Ti, Al, V)N layer satisfying specific composition formulas respectively; and (c) the lower-part layer is provided with a single phase structure, and is formed by vapor-depositing the hard covering layer composed of the (Ti, Al, V)N layer satisfying the composition formula: (Ti<SB>1-(E+F)</SB>Al<SB>E</SB>V<SB>F</SB>)N (wherein, E indicates 0.50-0.65 and F indicates 0.01-0.09 in terms of the atomic ratio). <P>COPYRIGHT: (C)2006,JPO&NCIPI

Description

  This invention has excellent lubricity of the hard coating layer, and therefore, even when used for high-speed cutting with high heat generation of difficult-to-cut materials with high viscosity such as mild steel, stainless steel, and even high manganese steel, The present invention relates to a surface-coated cemented carbide cutting tool (hereinafter referred to as a coated cemented carbide tool) that exhibits excellent chipping resistance without cutting chips adhering to the cutting edge during cutting.

  In general, coated carbide tools include a throw-away tip that is attached to the tip of a cutting tool for turning and planing of various steels and cast irons, and drilling of the work material. There are drills and miniature drills used for processing, etc., and solid type end mills used for chamfering, grooving, shoulder processing, etc. of the work material. A slow-away end mill tool that performs cutting work in the same manner as a type end mill is known.

In addition, as a coated carbide tool, a single-phase structure is formed on the surface of a cemented carbide substrate made of tungsten carbide (hereinafter referred to as WC) -based cemented carbide or titanium carbonitride (hereinafter referred to as TiCN) -based cermet. Have and
Composition formula: (Ti _{1− (X + Y)} Al _X V _Y ) N (wherein X is 0.50 to 0.65, Y is 0.01 to 0.09 in atomic ratio),
Coated carbide tool formed by vapor-depositing a hard coating layer composed of a composite nitride of Ti, Al, and V [hereinafter referred to as (Ti, Al, V) N] satisfying the above conditions with an average layer thickness of 2 to 8 μm The (Ti, Al, V) N layer has the characteristics that high temperature hardness and heat resistance are obtained by Al as a constituent component, high temperature strength is obtained by Ti, and lubricity is improved by V. It is also known that

Furthermore, the above-mentioned coated carbide tool is, for example, the above-mentioned carbide substrate is inserted into an arc ion plating apparatus which is one type of physical vapor deposition apparatus schematically shown in FIG. For example, an arc discharge is generated between the anode electrode and a cathode electrode (evaporation source) on which a Ti—Al—V alloy having a predetermined composition is set, for example, at a current of 90 A, while being heated to a temperature of 500 ° C. At the same time, nitrogen gas is introduced into the apparatus as a reaction gas to form a reaction atmosphere of, for example, 2 Pa. On the other hand, the carbide substrate is applied to the surface of the carbide substrate under a condition that a bias voltage of, for example, −100 V is applied. It is also known that it is manufactured by vapor-depositing a hard coating layer composed of the (Ti, Al, V) N layer.
Japanese Patent Laid-Open No. 10-237628

  In recent years, the performance of cutting devices has been dramatically improved, while on the other hand, there are strong demands for labor saving and energy saving and further cost reduction for cutting, and with this, cutting tends to be faster. In coated carbide tools, when used for cutting carbon steel, low alloy steel, and ordinary cast iron under high-speed cutting conditions, normal cutting performance is not a problem. Especially when cutting high-viscosity difficult-to-cut materials such as stainless steel and high-manganese steel under high-speed cutting conditions with high heat generation, the lubricity of the hard coating layer is insufficient. For this reason, the chips are likely to be welded to the cutting edge portion, which causes chipping (small chipping), and as a result, the service life is reached in a relatively short time.

In view of the above, the inventors of the present invention have developed the above-mentioned conventional coated super-hard tool in order to develop a coated carbide tool that exhibits excellent lubricity with a hard coating layer particularly in high-speed cutting of the difficult-to-cut material. As a result of conducting research by focusing on the (Ti, Al, V) N layer that constitutes the hard coating layer of hard tools,
(A) In the (Ti, Al, V) N layer constituting the hard coating layer, the lubricity is improved if the content ratio of the V component is increased, but 1 in the conventional (Ti, Al, V) N layer described above. When the V content is about 9 atomic%, high lubricity required for high-speed cutting of highly viscous difficult-to-cut materials cannot be ensured. To satisfy these requirements satisfactorily, It is necessary to contain 50 to 70 atomic% of V far exceeding 9 atomic%, while a (Ti, Al, V) N layer containing 50 to 70 atomic% of V component is put to practical use as a hard coating layer. In order to achieve this, it is necessary to contain a predetermined amount of Ti to ensure a predetermined high-temperature strength. In this case, however, it is inevitable that the content ratio of the Al component is extremely low. Be extremely low in nature.

(B) the composition _{formula: (Ti 1- (A + B} ) Al A V B) N ( provided that an atomic ratio, A is 0.01 to 0.10, B represents a 0.50 to 0.70) satisfies A (Ti, Al, V) N layer having a V content ratio of 50 to 70 atomic%;
Composition formula: (Ti _{1− (C + D)} Al _C V _D ) N (wherein, C is 0.25 to 0.40 and D is 0.20 to 0.35 in an atomic ratio), relative (Ti, Al, V) N layer with an increased Al component content,
Are alternately laminated in a state where each layer thickness is a thin layer of 5 to 20 nm (nanometers), the resulting (Ti, Al, V) N layer has the above-described structure due to the thin laminated layer structure. The excellent lubricity of the (Ti, Al, V) N layer (hereinafter referred to as the thin layer A) having a high V content, the V content ratio being relatively lower than that of the thin layer A, and relatively A predetermined relatively high high temperature hardness and heat resistance of the (Ti, Al, V) N layer (hereinafter referred to as the thin layer B) having a high Al content ratio.

(C) The (Ti, Al, V) N layer having the alternately laminated structure of the thin layer A and the thin layer B in (b) has excellent lubricity required for high-speed cutting of difficult-to-cut materials. However, since it does not have sufficiently satisfactory high-temperature hardness and heat resistance, it is provided as an upper layer of the hard coating layer, while the lower layer is insufficient in lubricity, but is relatively free of Al components. (Ti, Al, V) N layer having a high content ratio and having a composition corresponding to the above conventional hard coating layer having excellent high temperature hardness and heat resistance,
Compositional formula: (Ti _{1− (E + F)} Al _E V _F ) N (wherein E is 0.50 to 0.65 and F is 0.01 to 0.09 in terms of atomic ratio) (Ti, Al, V) N layer of single phase structure,
The resulting hard coating layer has high-temperature hardness, heat resistance, and high-temperature strength, in addition to excellent lubricity. The coated cemented carbide tool does not cause chips to adhere to the cutting edge even in high-speed cutting with the high heat generation of the above difficult-to-cut materials, resulting in excellent wear resistance without chipping. To come to show.
The research results shown in (a) to (c) above were obtained.

This invention was made based on the above research results, and on the surface of the carbide substrate,
(A) Both are composed of an upper layer and a lower layer made of (Ti, Al, V) N, the upper layer has a thickness of 0.5 to 1.5 μm, and the lower layer has a thickness of 2 to 6 μm. ,
(B) Each of the upper layers has an alternately laminated structure of thin layers A and B having a layer thickness of 5 to 20 nm (nanometer),
The thin layer A is
Composition formula: (Ti _{1− (A + B)} Al _A V _B ) N (wherein A is 0.01 to 0.10 and B is 0.50 to 0.70 in terms of atomic ratio) (Ti , Al, V) N layer,
The thin layer B is
Composition formula: (Ti _{1− (C + D)} Al _C V _D ) N (wherein C is 0.25 to 0.40 and D is 0.20 to 0.35 in terms of atomic ratio) (Ti , Al, V) N layer,
(C) the lower layer has a single phase structure;
Composition formula: (Ti _{1− (E + F)} Al _E V _F ) N (wherein E is 0.50 to 0.65 and F is 0.01 to 0.09 in atomic ratio) (Ti , Al, V) N layer,
It is characterized by a coated carbide tool that exhibits excellent chipping resistance in high-speed cutting of difficult-to-cut materials, which is formed by vapor-depositing a hard coating layer made of

Next, the reason why the numerical values of the hard coating layer of the coated carbide tool of the present invention are limited as described above will be described.
(A) Composition formula and layer thickness of the lower layer As described above, the Al component in the (Ti, Al, V) N layer constituting the hard coating layer improves high-temperature hardness and heat resistance, while the Ti component Has the effect of improving the high temperature strength and the lubricity of the V component, and the lower layer has a relatively high Al component content to provide high high temperature hardness and heat resistance. If the E value indicating the ratio is less than 0.50 in the ratio of the total amount of Ti and V (atomic ratio, the same shall apply hereinafter), the ratio of Ti is relatively high, which is required for high-speed cutting of difficult-to-cut materials. The excellent high-temperature hardness and heat resistance cannot be ensured, and the progress of wear is rapidly promoted. On the other hand, when the E value indicating the proportion of Al exceeds 0.65, relatively Ti As a result, the high-temperature strength suddenly drops Since chipping (slight chipping) or the like is likely to occur, the E value is set to 0.50 to 0.65.
Further, the F value indicating the proportion of V is the proportion of the total amount of Ti and Al, and if it is less than 0.01, the predetermined lubricity cannot be ensured, while the F value exceeds 0.09. Since the high temperature hardness and the heat resistance are drastically reduced, the F value is determined to be 0.01 to 0.09.
Furthermore, if the layer thickness is less than 2 μm, the excellent high-temperature hardness and heat resistance cannot be imparted to the hard coating layer over a long period of time, resulting in a short tool life, while if the layer thickness exceeds 6 μm Since the chipping is likely to occur, the layer thickness is set to 2 to 6 μm.

(B) Composition formula of upper layer thin layer A The V component in (Ti, Al, V) N of the upper layer thin layer A is remarkably increased in content as described above to improve lubricity. Therefore, it is contained for the purpose of adapting to high-speed cutting of difficult-to-cut materials with high heat generation. Therefore, if the B value is less than 0.50, the desired excellent lubricity cannot be ensured. If the value exceeds 0.70, the high temperature strength that the layer itself should have cannot be secured, and chipping is likely to occur. Therefore, the B value was set to 0.50 to 0.70.
Further, the A value indicating the proportion of Al is the proportion of the total amount of Ti and V. If it is less than 0.01, the minimum high-temperature hardness and heat resistance cannot be ensured, which causes accelerated wear. On the other hand, when the A value exceeds 0.10, a tendency to decrease in high-temperature strength appears, which causes chipping. Therefore, the A value was determined to be 0.01 to 0.10.

(C) Composition formula of thin layer B of the upper layer In the thin layer B of the upper layer, the content ratio of the V component is relatively lower than that of the thin layer A, and the content ratio of the Al component is relatively By keeping the thin layer A high, the thin layer A has insufficient high-temperature hardness and heat resistance, reinforces the high-temperature hardness and heat resistance shortage of the adjacent thin layer A, and thus has the excellent thin layer A. The upper layer having a relatively high high-temperature hardness and heat resistance of the thin layer B is formed, but the C value indicating the Al content in the composition formula is less than 0.25. , The predetermined high temperature hardness and heat resistance cannot be ensured, which causes wear promotion. On the other hand, when the C value exceeds 0.40, the high temperature strength rapidly decreases, Since chipping is likely to occur in the layer itself, the C value is 0.25. It was set to ˜0.40.
Further, the D value indicating the ratio of V is the ratio of the total amount of Ti and Al. If the value is less than 0.20, the lubricity of the entire upper layer is inevitably deteriorated, while the D value exceeds 0.35. Then, since the high temperature strength of the entire upper layer is drastically reduced, the D value was set to 0.20 to 0.35.

(D) Layer thicknesses of upper layer thin layer A and layer B If each layer thickness is less than 5 nm, it is difficult to form each thin layer clearly with the above composition. Excellent lubricity, further high temperature hardness and heat resistance cannot be ensured, and if the thickness of each layer exceeds 20 nm, each thin layer has defects, ie, if it is thin layer A, high temperature hardness and heat resistance Insufficient lubricity, if thin layer B, insufficient lubricity will appear locally in the layer, which may cause chipping and promote the progress of wear. It was set to ˜20 nm.

(E) Layer thickness of the upper layer If the layer thickness is less than 0.5 μm, it cannot provide its own excellent lubricity and predetermined high temperature hardness and heat resistance to the hard coating layer over a long period of time, resulting in a short tool life. On the other hand, if the layer thickness exceeds 1.5 μm, chipping tends to occur. Therefore, the layer thickness is set to 0.5 to 1.5 μm.

  In the coated carbide tool of the present invention, the hard coating layer is composed of a (Ti, Al, V) N layer. The upper layer of the hard coating layer has an alternate laminated structure of the thin layer A and the thin layer B. With excellent lubricity while maintaining the high temperature hardness and heat resistance of the single-phase structure, the lower layer of the same phase structure has excellent high temperature hardness and heat resistance. Even in high-speed cutting of difficult-to-cut materials with high heat generation, which easily causes chipping due to this, the hard coating layer does not generate chipping and exhibits excellent wear resistance over a long period of time It is.

  Next, the coated carbide tool of the present invention will be specifically described with reference to examples.

WC powder, TiC powder, ZrC powder, VC powder, TaC powder, NbC powder, Cr ₃ C ₂ powder, TiN powder, TaN powder and Co powder all having an average particle diameter of 1 to 3 μm are prepared as raw material powders. These raw material powders are blended in the composition shown in Table 1, wet mixed by a ball mill for 72 hours, dried, and then pressed into a green compact at a pressure of 100 MPa. Medium, sintered at 1400 ° C for 1 hour, after sintering, WC-based carbide with honing of R: 0.03 on the cutting edge and chip shape of ISO standard CNMG120408 Alloy carbide substrates A-1 to A-10 were formed.

In addition, as raw material powders, TiCN (mass ratio TiC / TiN = 50/50) powder, Mo ₂ C powder, ZrC powder, NbC powder, TaC powder, WC powder, all having an average particle diameter of 0.5 to 2 μm. Co powder and Ni powder are prepared, and these raw material powders are blended in the blending composition shown in Table 2, wet mixed by a ball mill for 24 hours, dried, and then pressed into a compact at a pressure of 100 MPa. The green compact was sintered in a nitrogen atmosphere of 2 kPa at a temperature of 1500 ° C. for 1 hour, and after sintering, the cutting edge portion was subjected to a honing process of R: 0.03 to obtain ISO standard / CNMG120408. The carbide substrates B-1 to B-6 made of TiCN base cermet having the following chip shape were formed.

(A) Next, each of the above carbide substrates A-1 to A-10 and B-1 to B-6 was ultrasonically cleaned in acetone and dried, and then the arc ion plate shown in FIG. Attached along the outer peripheral portion at a predetermined distance in the radial direction from the central axis on the rotary table in the coating apparatus, and used as a cathode electrode (evaporation source) on one side with the target compositions shown in Tables 3 and 4, respectively. As the upper layer Ti-Al-V alloy for forming the thin layer A having the corresponding component composition and the cathode electrode (evaporation source) on the other side, the component compositions corresponding to the target compositions shown in Tables 3 and 4 are also used. A Ti-Al-V alloy for forming a thin layer B, which is an upper layer, is arranged opposite to the rotary table, and a cathode is formed along the rotary table at a position shifted by 90 degrees from both the Ti-Al-V alloys. As an electrode (evaporation source) The section layer forming Ti-Al-V alloy is mounted,
(B) First, the inside of the apparatus is evacuated and kept at a vacuum of 0.1 Pa or less, and the inside of the apparatus is heated to 500 ° C. with a heater, and then the carbide substrate that rotates while rotating on the rotary table is set to −1000 V. And applying a current of 100 A between the Ti-Al-V alloy for forming the lower layer and the anode electrode to generate an arc discharge, so that the surface of the cemented carbide substrate is coated with the Ti-Al- Bombarded with V alloy,
(C) Introducing nitrogen gas as a reaction gas into the apparatus to make a reaction atmosphere of 3 Pa, applying a DC bias voltage of −100 V to a carbide substrate rotating while rotating on the rotary table, and A current of 100 A is passed between the Ti-Al-V alloy for layer formation and the anode electrode to generate an arc discharge, and the target composition and target layer thickness shown in Tables 3 and 4 are formed on the surface of the cemented carbide substrate. A (Ti, Al, V) N layer having a single phase structure is deposited as a lower layer of the hard coating layer,
(D) Next, nitrogen gas is introduced as a reaction gas into the apparatus to form a reaction atmosphere of 2 Pa, and a −100 V DC bias voltage is applied to a carbide substrate that rotates while rotating on the rotary table. A predetermined current in the range of 50 to 200 A is passed between the cathode electrode and the anode electrode of the Ti-Al-V alloy for forming the thin layer A to generate arc discharge, and the surface of the cemented carbide substrate is generated. A thin layer A having a predetermined thickness is formed, and after the thin layer A is formed, the arc discharge is stopped, and instead, the same is applied between the cathode electrode and the anode electrode of the Ti-Al-V alloy for forming the thin layer B. A predetermined current within a range of 200 A is applied to generate arc discharge to form a thin layer B having a predetermined layer thickness, and then the arc discharge is stopped (in this case, the formation of the thin layer B may be started). , Ti-A for forming the thin layer A again -Formation of thin layer A by arc discharge between cathode electrode and anode electrode of -V alloy and formation of thin layer B by arc discharge between cathode electrode and anode electrode of Ti-Al-V alloy for forming thin layer B An upper layer comprising alternating layers of thin layers A and B having a target composition and a target layer thickness of one layer shown in Tables 3 and 4 along the layer thickness direction is repeated on the surface of the cemented carbide substrate. Similarly, by carrying out vapor deposition with an overall target layer thickness shown in Tables 3 and 4, the surface-coated carbide throwaway tip (hereinafter referred to as the present invention coated carbide tip) 1 as the present invention coated carbide tool. ~ 16 were produced respectively.

  For the purpose of comparison, these carbide substrates A-1 to A-10 and B-1 to B-6 were ultrasonically cleaned in acetone and dried, respectively, and the arc ion plate shown in FIG. A Ti—Al—V alloy having a component composition corresponding to the target composition shown in Table 5 was installed as a cathode electrode (evaporation source) as a cathode electrode (evaporation source). The apparatus was heated to 500 ° C. with a heater while maintaining a vacuum of 1 Pa or less, and then a −1000 V DC bias voltage was applied to the carbide substrate, and the Ti—Al—V alloy and anode of the cathode electrode were applied. A current of 100 A is passed between the electrodes to generate an arc discharge, and the surface of the carbide substrate is bombarded with the Ti—Al—V alloy, and then nitrogen gas is introduced into the apparatus as a reaction gas to 3 Pa. And a bias voltage applied to the cemented carbide substrate is lowered to -100 V to generate an arc discharge between the cathode electrode and the anode electrode of the Ti-Al-V alloy, thereby the cemented carbide substrate. Each of A-1 to A-10 and B-1 to B-6 has a (Ti, Al, V) N layer having a single-phase structure having a target composition and a target layer thickness shown in Table 5. By forming the hard coating layer by vapor deposition, comparative surface-coated carbide throw-away tips (hereinafter referred to as comparative coated carbide tips) 1 to 16 as comparative coated carbide tools corresponding to conventional coated carbide tools are respectively provided. Manufactured.

Next, the coated carbide tips 1 to 16 of the present invention and the comparative coated carbide tips 1 to 16 of the present invention are screwed to the tip of the tool steel tool with a fixing jig. about,
Work material: JIS / SUS316 round bar,
Cutting speed: 240 m / min. ,
Cutting depth: 1.2mm,
Feed: 0.2 mm / rev. ,
Cutting time: 10 minutes,
Dry continuous high-speed cutting test of stainless steel under the conditions (cutting condition A) (normal cutting speed is 120 m / min.),
Work material: JIS · SCMnH2 lengthwise equidistant four round grooved round bars,
Cutting speed: 200 m / min. ,
Incision: 1.5mm,
Feed: 0.15 mm / rev. ,
Cutting time: 10 minutes,
Dry-intermittent high-speed cutting test of high manganese steel under the conditions (cutting condition B) (normal cutting speed is 100 m / min.),
Work material: JIS / SS400 round bar,
Cutting speed: 400 m / min. ,
Incision: 1.5mm,
Feed: 0.4 mm / rev. ,
Cutting time: 10 minutes,
The dry continuous high-speed cutting test (normal cutting speed was 200 m / min.) Of mild steel under the above conditions (cutting condition C) was carried out, and the flank wear width of the cutting edge was measured in any cutting test. The measurement results are shown in Table 6.

As raw material powders, medium coarse WC powder having an average particle diameter of 5.5 μm, fine WC powder of 0.8 μm, TaC powder of 1.3 μm, NbC powder of 1.2 μm, ZrC of 1.2 μm Powder, 2.3 μm Cr ₃ C ₂ powder, 1.5 μm VC powder, 1.0 μm (Ti, W) C [by mass ratio, TiC / WC = 50/50] powder, and 1 Prepare 8 .mu.m Co powder, mix these raw material powders with the composition shown in Table 7, add wax, ball mill in acetone for 24 hours, dry under reduced pressure, and then press at a pressure of 100 MPa. The green compacts were press-molded, and these green compacts were heated to a predetermined temperature in the range of 1370 to 1470 ° C. at a rate of temperature increase of 7 ° C./min in a 6 Pa vacuum atmosphere. After holding at temperature for 1 hour, sintering under furnace cooling conditions Three types of sintered carbide rod forming bodies for forming a carbide substrate having diameters of 8 mm, 13 mm, and 26 mm were formed, and further, the three types of round rod sintered bodies described above were subjected to grinding and shown in Table 7. Made of WC-base cemented carbide with a combination of 4 blade square shape with diameter and length of 6mm × 13mm, 10mm × 22mm, and 20mm × 45mm respectively, and a twist angle of 30 degrees. Carbide substrates (end mills) C-1 to C-8 were produced.

  Then, the surfaces of these carbide substrates (end mills) C-1 to C-8 were ultrasonically cleaned in acetone and dried, and then charged into the arc ion plating apparatus shown in FIG. Under the same conditions as in Example 1, a lower layer composed of a (Ti, Al, V) N layer having a single-phase structure with the target composition and target layer thickness shown in Table 8 is also shown along the layer thickness direction. A coated carbide tool of the present invention is formed by vapor-depositing an upper layer composed of alternating layers of thin layers A and B having a target composition shown in FIG. The present invention surface-coated carbide end mills (hereinafter referred to as the present invention coated carbide end mills) 1 to 8 were produced.

  For the purpose of comparison, the surfaces of the above-mentioned carbide substrates (end mills) C-1 to C-8 are ultrasonically cleaned in acetone and dried, and the arc ion plating apparatus shown in FIG. The hard coating layer made of (Ti, Al, V) N layer having a single phase structure having the target composition and target layer thickness shown in Table 9 is deposited under the same conditions as in Example 1 above. Thus, comparative surface-coated carbide end mills (hereinafter referred to as comparative coated carbide end mills) 1 to 8 as comparative coated carbide tools corresponding to conventional coated carbide tools were produced, respectively.

Next, of the present invention coated carbide end mills 1-8 and comparative coated carbide end mills 1-8, the present invention coated carbide end mills 1-3 and comparative coated carbide end mills 1-3 are as follows:
Work material-Plane: 100 mm x 250 mm, thickness: 50 mm, JIS / SUS304 plate,
Cutting speed: 60 m / min. ,
Groove depth (cut): 1.5 mm,
Table feed: 240 mm / min,
With respect to the dry high-speed grooving test of stainless steel under the conditions (normal cutting speed is 30 m / min.), The present invention coated carbide end mills 4-6 and comparative coated carbide end mills 4-6,
Work material-plane: 100 mm × 250 mm, thickness: 50 mm JIS / SCMnH2 plate material,
Cutting speed: 70 m / min. ,
Groove depth (cut): 3.5 mm,
Table feed: 230 mm / min,
For high manganese steel dry high-speed grooving test (normal cutting speed is 30 m / min.), Coated carbide end mills 7 and 8 of the present invention and comparative coated carbide end mills 7 and 8
Work material-plane: 100 mm × 250 mm, thickness: 50 mm JIS / SS400 plate material,
Cutting speed: 200 m / min. ,
Groove depth (cut): 8 mm,
Table feed: 480 mm / min,
The dry high-speed grooving test of mild steel under normal conditions (normal cutting speed is 100 m / min.) Is performed, and the flank wear width of the outer peripheral edge of the cutting edge is an indication of the service life in each grooving test. The cutting groove length up to 0.1 mm was measured. The measurement results are shown in Tables 8 and 9, respectively.

  The diameters produced in Example 2 above were 8 mm (for forming carbide substrates C-1 to C-3), 13 mm (for forming carbide substrates C-4 to C-6), and 26 mm (for carbide substrates C-). 7, for C-8 formation), from these three types of round bar sintered bodies, the diameter x length of the groove forming portion is 4 mm x 13 mm (by grinding), respectively. Carbide substrates D-1 to D-3), 8 mm × 22 mm (Carbide substrates D-4 to D-6), and 16 mm × 45 mm (Carbide substrates D-7 and D-8), and all Carbide substrates (drills) D-1 to D-8 made of a WC-base cemented carbide having a two-blade shape with a twist angle of 30 degrees were produced.

  Next, the cutting edges of these carbide substrates (drills) D-1 to D-8 are subjected to honing, ultrasonically cleaned in acetone and dried, and the arc ion plating apparatus shown in FIG. 1 is also used. A lower layer composed of a (Ti, Al, V) N layer having a single-phase structure having a target composition and a target layer thickness shown in Table 10 under the same conditions as in Example 1, and the same layer By vapor-depositing an upper layer composed of alternating layers of the thin layer A and the thin layer B having the target composition shown in Table 10 and a single target layer thickness along the thickness direction, with the overall target layer thickness also shown in Table 10, The surface coated carbide drills (hereinafter referred to as the present invention coated carbide drills) 1 to 8 as the present invention coated carbide tools were produced, respectively.

  For comparison purposes, the surfaces of the above-mentioned carbide substrates (drills) D-1 to D-8 are honed, ultrasonically cleaned in acetone, and dried, and the arc shown in FIG. A hard material comprising a (Ti, Al, V) N layer having a single-phase structure with the target composition and target layer thickness shown in Table 11 under the same conditions as in Example 1 above, while charging the ion plating apparatus. By vapor-depositing the coating layer, comparative surface-coated carbide drills (hereinafter referred to as comparative coated carbide drills) 1 to 8 as comparative coated carbide tools corresponding to conventional coated carbide tools were produced, respectively.

Next, of the present invention coated carbide drills 1-8 and comparative coated carbide drills 1-8, for the present invention coated carbide drills 1-3 and comparative coated carbide drills 1-3,
Work material-Plane: 100 mm × 250, thickness: 50 mm JIS / SS400 plate material,
Cutting speed: 90 m / min. ,
Feed: 0.2mm / rev,
Hole depth: 6mm,
About the wet high speed drilling cutting test of mild steel under the conditions of (normal cutting speed is 45 m / min.), The present invention coated carbide drills 4-6 and comparative coated carbide drills 4-6,
Work material-Plane: 100 mm × 250 mm, thickness: 50 mm JIS / SUS316 plate material,
Cutting speed: 55 m / min. ,
Feed: 0.1 mm / rev,
Hole depth: 10mm,
With respect to the stainless steel wet high speed drilling cutting test (normal cutting speed is 25 m / min.), The coated carbide drills 7 and 8 of the present invention and the comparative coated carbide drills 7 and 8
Work material-plane: 100 mm × 250 mm, thickness: 50 mm JIS / SCMnH2 plate material,
Cutting speed: 50 m / min. ,
Feed: 0.15mm / rev,
Hole depth: 20mm,
Wet high-speed drilling machining test (normal cutting speed is 25 m / min.) Of alloy tool steel under the above conditions, and the tip cutting edge surface in any wet high-speed drilling machining test (using water-soluble cutting oil) The number of drilling processes until the flank wear width was 0.3 mm was measured. The measurement results are shown in Table 8, respectively.

  (Ti, Al, V) of the coated carbide tips 1 to 16 of the present invention, the coated carbide end mills 1 to 8 of the present invention, and the coated carbide drills 1 to 8 of the present invention obtained as the coated carbide tools of the present invention obtained as a result. ) Comparison of coated carbide tip 1 as a comparative coated carbide tool equivalent to the conventional coated carbide tool, and the composition of the lower layer A and thin layer B constituting the hard coating layer made of N and the lower layer. -16, comparative coated carbide end mills 1 to 8 and comparative coated carbide drills 1 to 8 with a hard coating layer composed of (Ti, Al, V) N and an energy dispersion type using a transmission electron microscope When measured by X-ray analysis, each showed substantially the same composition as the target composition.

  Further, when the average layer thickness of the constituent layers of the hard coating layer was subjected to cross-sectional measurement using a transmission electron microscope, all showed the same average value (average value of five locations) as the target layer thickness.

  From the results shown in Tables 3 to 11, each of the coated carbide tools of the present invention has a single-phase lower layer composed of (Ti, Al, V) N, each having a hard coating layer having a different composition, and a layer thickness. Is composed of an upper layer having an alternating laminated structure of thin layers A and B each having a thickness of 5 to 20 nm, the lower layer has excellent high temperature hardness and heat resistance, and the upper layer has excellent lubricity. Since the hard coating layer combines these excellent properties, it is especially suitable for high-speed cutting with high heat generation of highly viscous difficult-to-cut materials such as mild steel, stainless steel, and high manganese steel. It exhibits excellent lubricity, chips do not adhere to the cutting edge during cutting, and exhibits excellent chipping resistance, whereas the hard coating layer has a single-phase structure (Ti, Al, V) The comparative coated carbide tool composed of the N layer The high-speed cutting of wood, chipping occurs in the cutting edge due to particularly lubricity shortage, it is apparent that lead to a relatively short time service life.

  As described above, the coated cemented carbide tool of the present invention is not only used for cutting under high-speed cutting conditions such as various carbon steels, low alloy steels, and ordinary cast iron, and particularly with high heat generation of difficult-to-cut materials. Therefore, it exhibits excellent chipping resistance even in high-speed cutting, exhibits excellent cutting performance over a long period of time, and has wide versatility with work materials, saving labor in cutting. And it can cope with energy saving and cost reduction sufficiently satisfactorily.

The arc ion plating apparatus used for forming the hard coating layer which comprises this invention coated carbide tool is shown, (a) is a schematic plan view, (b) is a schematic front view. It is a schematic explanatory drawing of a normal arc ion plating apparatus.

Claims (1)

On the surface of the cemented carbide substrate composed of tungsten carbide based cemented carbide or titanium carbonitride based cermet,
(A) All are composed of an upper layer and a lower layer made of a composite nitride of Ti, Al, and V (vanadium), the upper layer being 0.5 to 1.5 μm and the lower layer being 2 to 6 μm in thickness. Each with
(B) Each of the upper layers has an alternately laminated structure of thin layers A and B having a layer thickness of 5 to 20 nm (nanometer),
The thin layer A is
Ti satisfying the composition formula: (Ti _{1− (A + B)} Al _A V _B ) N (wherein A is 0.01 to 0.10 and B is 0.50 to 0.70 in atomic ratio) A composite nitride layer of Al and V;
The thin layer B is
Ti satisfying the composition formula: (Ti _{1- (C + D)} Al _C V _D ) N (wherein C represents 0.25 to 0.40 and D represents 0.20 to 0.35 in atomic ratio) A composite nitride layer of Al and V,
(C) the lower layer has a single phase structure;
Ti satisfying the composition formula: (Ti _{1− (E + F)} Al _E V _F ) N (wherein E represents 0.50 to 0.65 and F represents 0.01 to 0.09 in atomic ratio) A composite nitride layer of Al and V;
A surface-coated cemented carbide cutting tool that exhibits excellent chipping resistance in high-speed cutting of difficult-to-cut materials, formed by vapor-depositing a hard coating layer made of

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